ArchiCAD Question of the Day – May 11, 2014

Interior walls stick through the exterior in this ArchiCAD training question

In this section, I take a question submitted by a user and answer it, either in writing or with a video.

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Today’s question comes from Ben Jacks, a new ArchiCAD user who is going through my QuickStart Course on the ArchiCAD basics:

I have a wall “cleaning up” question. I am unsure if I should resolve it completely or let it go for now:

I have thick exterior walls with a reference line near but not on the outside of the wall. I have thinner interior walls with reference lines that are centered and sometimes on one side of the wall. The walls will eventually be completely different materials (at present they are generic exterior and interior. The are on different (exterior and interior) wall layers

They will not clean up. This is a perpendicular T.  I have tried using “adjust,” intersect, extending the interior manually to the inside, and stretching the reference of the interior to touch the reference of the exterior. Most times the interior wall lines go all the way through the exterior wall and stop at the outside line.

It seems an awkward workaround to stop the interior wall short of the inside.

Can you explain what is going on and what I should do?


The standard Graphisoft template for ArchiCAD 17 has an issue with regards to the intersection priorities for the generic interior and exterior Building Materials. The interior one has a higher priority than the exterior one, so if you’re using these generic materials, you experience this issue.

Fortunately, it is easily fixed. Select both an interior and an exterior wall, then open up the Options menu > Element Attributes > Building Materials. You’ll see the materials highlighted in green that are currently in use by the selected elements. Click on the Priority heading at the top of the list to sort by priority, rather than by name, then drag the Generic Exterior material below the Generic Interior one.


This will make ArchiCAD adjust the Intersection Priority for the exterior material to be higher than the interior material.

Click OK to confirm, and when you return to the floor plan, the walls will clean up the way you expect, with the interior ones giving way to the exterior ones, rather than going all the way through.


  • JasonSmith says:

    Another thing to check is the Layer Priority numbers are the same for the layer combination you are using.

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